Redundancy costs? Any time the marginal gas plants already there don't run, they are avoiding the likely staggering fuel costs of the future. That's a value, bolstered by their ability to be turned on when needed.

My point here is that (say) the costs of running a gas fired power station are 50% fixed, 50% variable (i.e. proportionate to the about of electricity produced - due mainly to the cost of the input fuel).

The Unit cost of electricity from such a plant operating at 10% capacity (i.e. only at times of extreme peak demand/low average wind speeds) is (50+50/10)/10 = 5.5 per 1% unit capacity

If that same plant is operating at 50% capacity the equivalent unit costs is (50+50/2)/50 = 1.5 per 1% unit capacity - in other words almost 4 times cheaper. Thus there is a marginal cost to maintaining more redundancy because of greater intermittency in the system.

"It's a mystery to me - the game commences, For the usual fee - plus expenses, Confidential information - it's in my diary..."

"Peaker" gas-fired power plants are already profitable while being used only 2-5% of the time. The reason for that is that they function only during price peaks, where peaks can be 50-100 times higher than normal prices for short periods. So they make enough money from very kWh, and overall emit very little carbon, while providing a vital service to the grid.

You're actually reinforcing my point that the higher the level of redundancy, the higher the UNIT cost of a peaker station - especially if they require 50-100 times higher than normal prices to maintain profitability. (In terms of carbon emissions they are, as you say, relatively insignificant).

This is in any case very much a secondary point. The greater point made above is that the wider the dispersal of windfarms and the larger the grid they are connected to, the less overall redundancy is required to provide a stable supply/demand platform.

"It's a mystery to me - the game commences, For the usual fee - plus expenses, Confidential information - it's in my diary..."